Conventionally, game machines, which embody, for example, shooting games, match-up combats, etc., output sounds when the ego character controlled by the player, any targets, other characters, etc. make an appearance or do some acts, from the speaker to which the game machine is connected, in order to increase the live feelings of the player and targets.
A technique for such sound output by a game machine is disclosed in the document indicated below.    Patent Literature 1: Japanese Patent No. 3455739
Other than the above, games today can output sounds by stereo reproduction or surround reproduction, etc., and an increasing number of games reproduce BGM or output sound effects for various objects (ego character, enemy character, other characters, targets of various kinds, etc.) that generate sounds.
Furthermore, by localizing a sound generator in a virtual two-dimensional space or a virtual three-dimensional space, it has become possible to make a sound effect of an object be heard from the direction in which the object exists.
In this case, sound information of the sound generated by each object is appropriately attenuated or phase-delayed in consideration of the positional information of the object, and after this, subjected to mixing to be output as the sound.